moved to general lucidness 
maybe you act differently or weirdly IRL when you have a lucid dream.
anyone ever checked that out? like, maybe you start sleepwalking and sort of “act out” your LD. 
just a thought…
When you’re dreaming, your body is paralyzed. So you will be unable to move.
There’s a thing called Sleepwalking 
I was more thinking of the topic title “Have you ever watched a person have a LD?”, once in my ND a DC were lucid and walked around bragging about it.
Sleepwalking occurs during Deep sleep, Mainly the 3rd stage of the 90 minuite sleep cycle. A lucid dream is during REM, which is why you have Sleep paralysis. You occassionaly dream during Deep sleep, but you never remember it.
hmm. this is a pretty good question. i havent though. they probably are just exactly the same. but theres a chance maybe their eyes are moving differently, like more furiously since usually lucid dreamers are looking around a lot. I also wouldnt be surprised if lders had an increased heart rate.
Actually I read that LDs are slower then NDs. Where you can experience hours in the space of seconds in a ND, you would only experience seconds in a LD. However, there have been people that have overcome that.